To provide a plotting method for changing a picture according to detection data such as the moving speed of the pen top of an input pen.

A device is provided with a pen top movement detecting means 60 and a picture changing means 70 which are controlled by a picture editing means 10. When a user performs the pen-up of an input pen while moving the pen top of the input pen in performing the pen-down of the input pen in order to make a picture display means 20 display the picture, the pen top operation detecting means 60 detects the moving speed and direction of the pen top on the basis of a plurality of coordinates measured by a coordinate inputting means 20 with predetermined time intervals. The picture changing means 70 generates plotting data for changing the picture on the basis of the moving speed and direction of the pen top.